There are quite simply a lot more banks and other financial institutions that issue credit cards. When I lived in the UK there were essentially 4 banks, plus a

There are quite simply a lot more banks and other financial institutions that issue credit cards. When I lived in the UK there were essentially 4 banks, plus a dozen building societies (US equivalent: credit union). Today the US has about 6,000 banks and similar number of credit unions. In order to get customers they have to stand out from their competitors which means marketing, card perks and rewards. With that much activity, it is almost inevitable that people will end up with more cards. Americans also like their stuff complicated. Look at health care and politics as two examples. What it often manifests itself as is different choices for different circumstances, whereas others would lump it all together. For example you generally don't have a single "bank account", but instead you have a checking account and a savings account, not necessarily at the same bank even! And yes there is federal law around what constitutes a savings account. When making a purchase, the optimum card to use will vary. For example a store affinity card will likely offer discounts at that store and affiliated ones. Some offer cashback but it varies by category (eg it may be 5% for petrol stations, 2% for restaurants, 1% for supermarkets) with each having its own percentages and other limitations (eg min quantities, max cash back). And if you are saving up airline miles, you may want to use that relevant card instead of the others until hitting your goal. I try to keep my cards to an absolute minimum but ended up with 4 all from my bank: a debit/atm card, another one tied to my health savings account (which has to be different), a credit card, and a second backup credit card.